(http://imgur.com/MnOLN26)
Eredin calls down meteors during the final battle with Geralt. In case there's any doubt about them being meteors? The Guide confirms they're meteors.
After a teleport, Eredin can also call down a storm of ice-laden meteors.
As with the meteors, getting harmed by this will partially freeze Geralt and make him much slower on his feet.
The same exact description is repeated later on.
So yes, Eredin is calling down meteors. The Thermosphere, the highest part of the Earths atmosphere, is
375 miles (603.50400km) away at it's furthest.
Timeframe is 3 seconds and 14 frames.
T = 1s/24
= 41.6666667ms X 14
= 0.583333334s + 3s
= 3.58333333s
T = 603.50400km/3.58333333s
= 168419.721/340.29
= Mach 494.929974
Final Results
Eredin calls down meteors = Mach 494.93